The glossary below contains many of the terms you will find in common use throughout the Symantec Security Response website. Please refer to this list to find definitions of terms and answers to other Internet security-related questions.


Extensible malicious code can dynamically change its behavior via modules or by updating itself by downloading code from outside the system. For example it may download new modules via the Web, email, USENET (NTTP), Napster, etc. For example, the W32/Hybris worm can download plug-ins from the newsgroup or from a Web site.